PMG Variable Speed Generator Control Processor for Aircraft
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Solution Overview
Problem
Existing aircraft electrical power generation systems, particularly those using 3-stage wound synchronous generators, are complex and heavy, adding substantial load to the aircraft's wings due to their requirement for constant speed inputs and outputs, which complicates the design and increases weight.
Innovation Solution
Implementing a PMG (permanent magnet generator) variable speed constant frequency generating system with a control processor that electronically controls the output frequency and voltage, eliminating the need for an exciter stage and reducing the system's complexity and weight by directly correlating input speed with output power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a 3-stage wound synchronous generator is used to produce constant frequency power, then the output power characteristics are stable, but the system becomes complex and heavy, adding substantial load to the aircraft wings
Solution Approach 1:
The patent extracts and eliminates the exciter stage from the traditional 3-stage wound synchronous generator system, reducing it to a simpler PMG (permanent magnet generator) configuration. This removal of the exciter component directly reduces system weight and complexity while maintaining the constant frequency power output capability through electronic control of the PMG.
Solution Approach 2:
The patent replaces the mechanical exciter system with an electronically controlled PMG system. Instead of using a mechanical exciter to provide field current, the invention uses electronic control circuitry to regulate the PMG output, substituting mechanical complexity with electronic control while achieving the same constant frequency power generation function.
2Reliability
If a 3-stage wound synchronous generator is used to produce constant frequency power, then the output power characteristics are stable, but the device complexity increases due to multiple stages and heavy gear boxes
Solution Approach 1:
The patent removes the exciter stage from the generator system, simplifying the structure from three stages to a single PMG stage. This extraction eliminates the complexity associated with the exciter while maintaining constant frequency output through electronic control of the PMG.
Solution Approach 2:
The invention replaces the mechanical multi-stage generator structure with a single PMG stage controlled by electronic circuitry. This substitution eliminates heavy mechanical gear boxes and complex mechanical linkages, reducing device complexity while preserving the constant frequency power generation capability.
3Reliability
If constant speed drives and integrated drive generators are used to drive generators, then constant speed input is provided for power production, but heavy mechanical gear boxes are required that add unwanted loads to the aircraft wings
Solution Approach 1:
The patent replaces the mechanical constant speed drive system with an electronically controlled PMG system. Instead of using heavy mechanical gear boxes to maintain constant speed, the invention uses electronic control circuitry to regulate the PMG output frequency and voltage, eliminating the need for mechanical speed regulation mechanisms and reducing the load on aircraft wings.
Solution Approach 2:
The invention changes the control parameter from mechanical speed regulation to electronic frequency and voltage control. By controlling the electrical parameters (frequency and voltage) directly through electronic circuitry rather than regulating mechanical speed, the system eliminates the need for heavy mechanical gear boxes while maintaining constant frequency power output.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution simplifies the power generation system, reduces weight, and increases volumetric power density by using a lighter and smaller PMG, allowing for electronic control of output frequency and voltage, thereby reducing the overall load on the aircraft's wings while maintaining constant power characteristics.
Implementation Method 1
A PMG is a single state generator with an output voltage and frequency that directly corresponds to the input speed
Implementation Method 2
The frequency and voltage of the output power are controlled electronically by a control processor
Data Source
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AI summary
In accordance with one or more embodiments, a method for implementing a PMG variable speed constant frequency generating system on an aircraft including an aircraft engine is provided. The method includes receiving AC power from a PMG at an AC/DC conversion stage, the received power being proportional to a rate of rotation of the aircraft engine and converting the AC power to DC power in the AC/DC conversion stage. The method further includes sensing a DC voltage output by the AC/DC conversion stage and providing the DC voltage to a DC/AC conversion stage. The method includes providing a control signal to the DC/AC conversion stage to control a frequency and a voltage of an output signal of the DC/AC conversion stage without varying an electrical signal provided to the PMG.